package Java基础.集合.HashMap;

import org.junit.jupiter.api.Test;

import java.util.HashMap;

/**
 * Created by didi on 11/01/2018.
 */
public class TestHashMap {

    @Test
    public void test(){
        HashMap<String,String> map = new HashMap<>();
        map.put(null,"1");
        map.put(null,"2");
        System.out.println(map.get(null));
    }
}
